The WR450F was already a proven leader in the big-bore off-road world, but for 2006, we decided to bump up the Nasty-Meter.

A lower overall frame and seat height means that it’s easier to get down and dirty on your favourite trail. Slimmer rad shrouds, seat and fuel tank mean that you’ve got more room to manouver – if you can catch your breath. Larger, fully-adjustable 48mm fork and lighter Renthal aluminum handlebars give you precise control of this trail taming beast. Once you fire up the 5-valve 4-stroke with the touch of the reliable electric starter, you’ll notice that we’ve also added carb and ignition settings. The perfect bike just upped the ante.

Titanium valves and load-reduced springs decrease weight by more than 40% over a conventional valve train and reduce reciprocating mass for faster-revving, smoother-hitting power delivery across the rev range.

Special cylinder design features cutaways that allow the air trapped under the piston to enter a side chamber (or cutaway) to reduce horsepower-robbing “pumping losses.”

Lightweight crankcase also utilizes cutaways to reduce “pumping losses.” The crankcase cutaways match the cutaways in the cylinder.

Washable, dual-stage, foam air filter features tools-free to access to the airbox and filter.

Revised header pipe features a specially shaped header angle maximizes engine power and allows hassle-free replacement of the oil filter. The header pipe is made of stainless steel and features a heat shield. This system maximizes engine power and allows hassle-free replacement of the oil filter.

Lightweight aluminum wrapped muffler optimizes both power delivery and appearance. This muffler design features a “serviceable”, screen-type spark arrestor which prevents sparks from exiting the exhaust. Its repackable design means you can maintain optimal engine performance and reduce noise levels.

Trick, works-style clutch lever features an oversize “barrel adjuster” for easy, on-the-fly adjustability of lever/cable play. There is a new, larger boot covering the adjuster that provides more grip for easier operation.

Removable, aluminum, rear sub frame constructed of square-section pipe reduces weight and provides easy rear suspension access. For 2005, new conventional hex head bolts have replaced the Allen-style bolts that secure the sub frame to the main frame for easier, faster servicing.

New, lightweight, tapered, aluminum swingarm is produced using “hydro forming”, a special forming method that uses high pressure water to form shapes. The new swingarm provides improved overall chassis balance thanks to the addition of re-enforcing ribs in the cast aluminum around the pivot area. The result is a 2% increase in torsional rigidity for improved handling.

Revised 48mm, adjustable, inverted Kayaba cartridge fork provide excellent suspension performance. The outer (male) tube is changed to optimize rigidity and is Kashima coated to reduce friction.(changed from Alumite) . The center rod size has been reduced form 8mm to 6mm while the cylinder diameter has been increased from 25 to 28mm. This new fork no only offers excellent suspension function but also reduces weight too.

A new oil lock system in the new fork is now utilized. This new oil lock system enhances suspension performance and improves rider comfort.

The 48mm fork utilizes a Transfer Control Valve (TCV) which enhances the damping force from mid stroke to full stroke and improves bottoming characteristics. The benefit of TCV is more precise control throughout the full stroke range.

New larger plastic fork protectors wrap further around the fork tubes for increased protection. They are self-supporting design to reduce friction for smoother fork operation. The routing of the wiring for the new electric speed sensor (no longer a traditional cable) now passes on the inside of the fork leg protector for added protection.

Revised 245mm rear disc brake utilizes a new single piston caliper. The caliper is mounted lower on the swingarm to add additional clearance for the exhaust pipe. The rear master cylinder is integrated with the fluid reservoir to reduce weight. This revised set-up delivers strong, progressive stopping power with excellent control and feel.

All new multifunction digital meter assembly. This compact meter features 2 modes. The first is the “basic” mode and features: speedometer, odometer, resettable dual tripmeters, and a clock. The second is the race mode and it features speed, an automatic start timer, and the ability to edit the tripmeters and an odometer.

New design front fender and seat. The seat base and foam has been revised for more cushioning effect and improved rider comfort.

Sun Star specially designed rear sprocket increases the contact area between the sprocket and chain rollers, thereby reducing the load on the chain and increasing service life of both chain and sprocket.

The regulator has been re-located to the steering head area.

Features:

Premium Dunlop knobbies offer great traction and excellent wear.

“Slim line” bodywork is very similar to the YZ bodywork. The fuel tank capacity is 8 litres. The “slim line” body allows fast, easy rider movements and a lighter overall machine feel.